Pro-Russian demonstrators march with a huge Russian flag during a protest in front of a local government building in Simferopol, Crimea, Ukraine on Thursday. Photo: AP

AP

A Pro-Russian demonstrator waves Russian and Crimea flags from an old Soviet Army tank during a protest in front of a local government building in Simferopol, Crimea, Ukraine, on Thursday. Ukraine's acting interior minister says Interior Ministry troops and police have been put on high alert after dozens of men seized local government and legislature buildings in the Crimea region. Photo: AP

Simferopol airport operations reported normal after armed men, wearing similar gear to a group of 100 gunmen who stormed the Crimean parliament and raised the Russian flag, entered the building

Russian military were blocking an airport in the Black Sea port of Sevastopol in Crimea, near the Russian naval base, while unidentified men were patrolling another airport serving the regional capital Simferopol, Ukraine’s new Interior Minister Arsen Avakov said on Friday.

Mr. Avakov wrote in a Facebook post that the Belbek international airport in Sevastopol was blocked by military units of the Russian navy. “I can only describe this as a military invasion and occupation,” he said.

The Russian foreign ministry refused to comment while a spokesman for the Russian defence ministry was not available for comment.

Early on Friday, around 50 armed men in military uniform arrived in three trucks without licence plates and surrounded the domestic flights terminal at the airport of Simferopol, the regional capital of Crimea, before moving on to other parts of the site, Interfax-Ukraine news agency cited witnesses as saying.

An Associated Press photographer saw military men armed with assault rifles on Friday morning patrolling the airport. The men, who were wearing uniforms without any insignia, refused to talk to journalists, and it was not immediately clear who they were.

The men wore similar gear to a group of 100 gunmen who stormed the Crimean parliament on Thursday and raised the Russian flag over the building, the report said.

The armed men since left the building, according to broadcaster Russia Today.

The airport appeared to be operating normally, with flights landing and taking off, RIA-Novosti news agency quoted a worker at the airport as saying. The airport’s website showed flights arriving and departing on schedule.

On Thursday, masked gunmen with rocket-propelled grenades and sniper rifles seized the parliament and government offices in Simferopol and raised the Russian flag over the parliament building.

The events in the Crimea region have heightened tensions with neighbouring Russia. It scrambled fighter jets on Thursday to patrol borders in the first stirrings of a potentially dangerous confrontation reminiscent of Cold War brinksmanship.

Russia also has granted shelter to Ukraine’s fugitive president, Viktor Yanukovych, after recent deadly protests in Kiev swept in a new government.

Mr. Yanukovych has a news conference scheduled Friday in Russia’s south near the Ukrainian border. He has not been seen publicly since Saturday, and he declared on Thursday in a statement that he remains Ukraine’s legitimate president.

Ukraine’s parliament on Thursday elected a new government led by a pro-Western technocrat who promptly pledged to prevent any national break-up.

Moscow has been sending mixed signals about Ukraine but pledged to respect its territorial integrity. Ukraine’s population is divided in loyalties between Russia and the West. Crimea, which was seized by Russian forces in the 18th century under Catherine the Great, was once the crown jewel in Russian and then Soviet empires.

It only became part of Ukraine in 1954 when Soviet leader Nikita Khrushchev transferred jurisdiction from Russia, a move that was a mere formality until the 1991 Soviet collapse meant Crimea landed in an independent Ukraine.

In a bid to shore up Ukraine’s fledgling administration, the International Monetary Fund has said it is “ready to respond” to Ukraine’s bid for financial assistance. The European Union is also considering emergency loans for a country that is the chief conduit of Russian natural gas to Western Europe.

Ukraine’s finance ministry has said it needs $35 billion over the next two years to avoid default.